# The Impact of Healthcare Exposure on Colonization with Antiseptic Tolerant Staphylococci in Children

> **NIH AHRQ R01** · BAYLOR COLLEGE OF MEDICINE · 2021 · $481,205

## Abstract

One of the strategies commonly used to mitigate healthcare associated infections (HAIs) and decrease pathogen
colonization burden relies on topical antiseptic agents, including chlorhexidine gluconate (CHG). While there is
clear benefit from the use of these agents, concern exists for the potential for microbial adaptation, as is the case
with virtually every antibiotic. A number of genes encoding multidrug efflux pumps in Staphylococcus aureus,
including qacA/B and smr, have been associated with elevated MICs to antiseptics with such organisms often
termed antiseptic tolerant S. aureus (ATSA). A study of S. aureus infections in pediatric oncology patients
revealed an increase in ATSA following an escalation in CHG use. Among S. aureus infections, the presence
of antiseptic tolerance (AT) genes is independently associated with nosocomial acquisition of infection and
underlying medical conditions. Importantly, ATSA are also associated with resistance to systemic antimicrobials
and invasive infection. These data support the concept of the healthcare environment selecting for organisms
with reduced susceptibility to antiseptics, which in turn are associated with a severe disease phenotype. AT
genes have likewise been reported in other important HAI pathogens including coagulase-negative staphylococci
(CoNS). Notably, there are few longitudinal studies which assess the impact of repeated healthcare or antiseptic
exposure on colonization with these organisms. Furthermore, the exact impact of AT genes on the efficacy of
antiseptics is controversial given the very high concentrations used in practice. Thus, a better understanding of
these unintended consequences of infection prevention measures and their clinical relevance is necessary and
within the mission of AHRQ and the FOA. Our long-term goal is to develop a greater understanding of the factors
promoting antiseptic/antibiotic resistant infections. We hypothesize that the healthcare environment and medical
complexity predispose to the acquisition of antiseptic tolerant organisms (ATOs) in children. We propose a
prospective cohort study to longitudinally examine colonization with ATOs. Children with a new diagnosis of
malignancy (high-risk cohort) as well as healthy children (low-risk cohort) will be enrolled; both groups will have
nasal and axillary cultures obtained at three-month intervals over one year. Specific Aim 1 will assess the rate
of colonization with ATSA in the high-risk cohort compared to the low-risk cohort with a goal of determining the
point at which risk for acquisition increases in the high-risk cohort. Specific Aim 2 will explore the disease causing
potential of ATSA by examining incident infection rates in enrolled subjects with respect to ATSA colonization
status, as well as through microbial genomic studies. Specific Aim 3 will examine the impact of AT genes on
survival of S. aureus following exposure to clinically relevant antiseptic solutions in a catheter disinfection assay...

## Key facts

- **NIH application ID:** 10141233
- **Project number:** 5R01HS026896-03
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **Principal Investigator:** Jonathon Chase McNeil
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** AHRQ
- **Fiscal year:** 2021
- **Award amount:** $481,205
- **Award type:** 5
- **Project period:** 2019-07-01 → 2024-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10141233

## Citation

> US National Institutes of Health, RePORTER application 10141233, The Impact of Healthcare Exposure on Colonization with Antiseptic Tolerant Staphylococci in Children (5R01HS026896-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10141233. Licensed CC0.

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